1. Field of the Invention
The present invention relates to a developing apparatus and a developer container provided in image forming apparatuses such as copiers, facsimiles, and printers, and an image forming apparatus provided therewith.
2. Description of Related Art
There have conventionally been proposed various image forming apparatuses provided with a developing device (hereinafter referred to as a developer unit) that is detachably fitted to an apparatus main body and a developer container (hereinafter referred to as a toner cartridge) that is detachably fitted to the developer unit (see, for example, Japanese Patent Application Laid-Open No. H9-146366).
In such an image forming apparatus, detaching the developer unit with the toner cartridge connected thereto from the apparatus main body has an advantage in preventing spattering and leakage of toner, because this eliminates the trouble of reshielding a portion at which the developer unit and the toner cartridge connect together.
However, the problem here is that, due to the easiness of connecting the developer unit and the toner cartridge together, there is a possibility that the toner cartridge comes off and falls to the ground if the connection release mechanism is touched unconsciously when the developer unit is carried about.
On the other hand, there is a possibility that foreign matters enter a toner feed port, a drive member, and the like when the developer unit, having the toner cartridge completely detached therefrom, is left untouched. In that case, when the developer unit is refitted to the image forming apparatus main body so as to obtain an image, there is a possibility of causing degradation in image quality, abnormal sounds, and what is worse, a breakdown of the apparatus.
In view of the conventionally experienced problems described above, it is an object of the present invention to provide a developing apparatus that can prevent a toner cartridge from inadvertently coming off a developer unit if the developing apparatus is in a state detached from a main body of an image forming apparatus.